#include<stdio.h>
#include<string.h>
#include<unistd.h>

int main(int argc, char* argv[], char* env[])
{
    sleep(30);
    printf("change begin\n");
    if(argc == 2)
    {
        chdir(argv[1]);
    }
    printf("change end\n");
    sleep(30);
    return 0;
}
